Cut-off mechanism



(No Model.)

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ATTORNEYS.

UNITED STATES ATENT firmen.

CUT-OFF MECHANISM.

vSPECIFICATION forming part of Letters Patent No. 272,797, datedFebruary 20, 1883.

Application filed November 20, 1882. (No model.)

To all whom 'it may concern Be it known that LJAMns THOMAS, ofCatasauqua, in the county of Lehigh and State of Pennsylvania., haveinvented a new and Improved (Jut-Ott' Mechanism ibrSteain-Engines, ofwhich the lollowing is a t'ull, clear, and exact description.

The object of my invention is to combine simple and inexpensive cut-offgearing with an ordinary slide-valve for governing the amount ot steamadmitted to the engine-cylinder. y

My invention consists in a cylindrical valve combined with aslide-valve, so as to be operated by a governor to regulate the amountot' steam passing through the slide-valve to the engine, as hereinafterdescribed and claimed.

Reference is to be had to the accompanying drawings, forming a part ofthis specitication, in which similar letters of reference indicatecorresponding parts in all the tignres.

Figure 1 is a longitudinal section of an enginecylinder andsteaiii-chest provided with my improved valve mechanism. Fig. 2 is across-section on the line a; ac.V Fig. 3 is a crosssection on the line yy, Fig. l; and Fig. 4 is a cross-section of the valves on line z z. Fig.1.

The cylinder L and steam-chest M may be of any ordinary or desiredconstruction.

B B are the slide-valves, fitted upon the one valve-rod, and A A are thecut-oli' valves that are combined with the slide-valves. as shown mostclearly in Figs. 2 and 4. Each sidevalve B is formed hollow to givespace for the passage of the steam, there being a middle partition thatseparates the live from the eX- haust steam passages. The valve is alsoformed with a cylindrical seat for the valve A, which is also ofcylindrical form and hollowed out or recessed at its ends.

In the sides of the valve A, and also in the seat, are steam-ports G Cand E E, which,

when brought in register, allow passage of the steam from thesteam-chest to the interior of the valve B. The two valves A A are looseupon a square stem or rod, F, which is supported at its ends by bearingsDin the ends of the steam-chest.

The valves A are kept in place by lips m and rings n upon the valves B,so that the cutoftsshall move with the slide-valves, but are free torotate in their seats with the stem, which is also free to rotate iiiits bearings, but has n0 endwise movement. At its mid-length is asleeve, H, to which is attached a rod, l, that passes out through thesteam-inlet ot' the chest directly to the governor'.

In operation any variation of the speed ot' the engine is communicatedby the governor, through the rod I, to the stem F and cut-ofi' valves A,which, being thus rocked, open and close the slots() and E more or less,thus admitting or cutting oli' the supply ot' steam.

I do not limit myself to the especial construction and arrangement ot'the parts as shown, as they maybe varied within the scope of myinvention.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent- The combination, with a hollow slide-valvehaving the lips m and rings n, and the squared rocking shaft F, ofthehollow rocking cut-otl' valve Adivided transversely and open at theends, the two valves being provided with registering ports O E, asshown, whereby the cutoft' valve maycarry the slide-valve on the stem Fand be rocked within it by the stem, as described.

JAMES THOMAS.

Witnesses:

GEo. W. BOWER, Jr., J. H. FRAUNcEs.

